Is it actually waterproof? March 29, 2018 03:40 Updated Follow We've done our research and can confirm they are 100% waterproof - creating the perfect barrier from spills and stains. Related articles What is the protector made of? Why should I choose a Simba Mattress Protector? What certifications does the protector have? How do I use my Simba Mattress Protector? How long does the Aloe Vera last?